[Zurück]

C. Knoll, G. Gravogl, W. Artner, E. Eitenberger, G. Friedbacher, A. Werner, R. Miletich, P. Weinberger, D. Müller, M. Harasek:
"Metal oxides for thermochemical energy storage - From gas-triggered isothermal cycling to low-temperature applications with increased O₂ pressure";
ISES Solar World Congress Proceedings, 1 (2017), S. 811 - 820.

Metal oxides providing various, reversibly accessible oxidation states are in the focus as auspicious materials for high-temperature thermochemical energy storage (TCES) materials. Among all principally suitable metal oxides due to equilibrium temperature and, in particular, reaction rate and reversibility, only the couple Co₃O₄ / CoO and to a smaller extend Mn₂O₃ / Mn₃O₄ are considered as suitable candidates. Based on recent studies on isothermal TCES-cycles, the impact of temperature and increased O₂-pressure on the reaction rate was investigated by
varying the O₂-partial pressure in the low-temperature oxidation of the reduced oxide. Whereas Mn₃O₄ was found to react too slow for a process at lower temperatures, CoO was found suitable. For an increase of the O₂ pressure to 6 bar between 500 - 550 °C an attractive oxidation behavior was observed. At 900 °C Co₃O₄ / CoO could be cycled within 4.5 minutes between both oxidation states by changing the atmosphere from N₂ to O₂ and vice versa.

cobalt oxide, manganese oxide, non-ambient pressure, in-situ powder X-Ray diffraction, thermochemical energy storage

http://dx.doi.org/10.18086/swc.2017.14.02